Patent GB-709455-A (GB)
Title: Water-soluble asymmetric ureas and thioureas and a process for their production
IPC: C07C335/16
Filed: 1951-12-13
Abstract: Condensation products which are asymmetric ureas or thioureas are obtained by treating o-amino-sulphonic acids of the benzene series with aromatic carbonic or thiocarbonic acid derivatives; the products contain one or more trifluoromethyl groups.  The same products are obtained by using aromatic carboxylic acid azides or N-halo-amides as acylating agents, or by reacting urethanes of the o-aminosulphonic acids with aromatic amines.  Further halogen atoms may be introduced into the products.  Suitable carbonic acid derivatives are halides, esters and amides, carbon disulphide, isocyanates and isothiocyanates.  In the examples the following are reacted: (1) 3 : 4-dichloraniline - 6 - sulphonic acid and 4 - chloro - 3 - trifluoromethyl-phenyl isocyanate; (2) amine of (1) and 3 : 5-bis-trifluoromethyl-phenyl isocyanate; (3) 4-chloro-3-trifluoromethylaniline-6-sulphonic acid and 3 : 4-dichlorophenyl isocyanate; (4) amine of (3) and isocyanate of (2); (5) amine of (3) and isocyanate of (1); (6) amine of (3) and 3-trifluoromethyl-phenyl isocyanate; (7) 2 - chloro - 5 - trifluoromethylaniline - 6 - sulphonic acid and 2-chloro-5-trifluoromethylphenyl isocyanate; (8) amine of (7) and isocyanate of (1); (9) amine of (7) and isocyanate of (2); (10) 3 : 4-dichloro-6-sulpho-phenylcarbamic phenyl ester and 3-trifluoromethyl-4-chloraniline; (11) amine of (3) and 3 : 4-dichlorobenzoyl azide; (12) amine of (3) and 4-chlorobenzoic chloramide; (13) amine of (3) and 4-chlorophenyl isothiocyanate; (14) 4-amino - 2 : 41 - dichloro - diphenylether - 5 - sulphonic acid and isocyanate of (1); (15) 4-amino-41-chloro-diphenylether-5-sulphonic acid and 3 : 5 - dimethyl - 41 - trifluoromethyl - diphenyl-ether-21-isocyanate; (16) 4-amino-2 : 41 : 51-trichlorodiphenylether-5-sulphonic acid and isocyanate of (1); (17) amine of (14) and 3-trifluoromethylphenyl isothiocyanate; (18) 2 : 41-dichloro - 5 - sulpho - diphenylether - 4 - carbamic phenyl ester and amine of (10); (19) 4-amino - 51 - methyl - diphenylether - 5 - sulphonic acid and amine of (1), the product being chlorinated; (20) 2 - amino - 4 : 41 - dichloro - diphenylether-3-sulphonic acid and isocyanate of (7); (21) 4-amino-21 : 41-dichloro-diphenyl-ether-5-sulphonic acid and isocyanate of (1); (22) amine of (15) and isocyanate of (6); (23) 4-amino - 2 : 21 : 41 - trichloro - diphenylether - 5 - sulphonic acid and isocyanate of (2).  Other suitable components and products are listed.  The preparation of similar compounds without the trifluoromethyl group is acknowledged, e.g. in Specifications 536,011 and 536,047.  The above isocyanates and isothiocyanates are made by known methods from the corresponding amines via the carbamic acid chlorides, for example 4-chloro-3-trifluoromethylphenyl isocyanate.  A list of suitable amines is given. The amine of example 7 is made by sulphonation of 2-chloro-5-trifluoromethylaniline.  The amine of example 14 is made by condensing p-chlorophenol with 3 : 4-dichloronitrobenzene-6-sulphonic acid and reducing the product. Other amines may be made in the same way.  The urethane of example 18 is prepared from the corresponding amine and phenyl chloroformate.